U.S. Pat. No. 4,273,634 to Saam et al. teaches an aqueous silicone emulsion which provides an elastomeric product upon removal of the water under ambient conditions. The emulsion comprises a continuous water phase and a dispersed phase of crosslinked silicone. The silicone phase is the product of free radical produced crosslinking of hydroxyl endblocked polydiorganosiloxane. The polydiorganosiloxane is crosslinked after it has been dispersed in water. Preferred polydiorganosiloxanes contain vinyl-substituted siloxane units and can be crosslinked by high energy radiation or the combined action of heat and an organic peroxide. However, the present invention is distinguished from the '634 patent because the present invention teaches a method of placing the functionalizing silane on the ends of the polydiorganosiloxane molecule, rather than randomly on the polydiorganosiloxane molecule as disclosed in the '634 patent. Also, the '634 patent discloses precuring the polydiorganosiloxane emulsion, whereas the present invention does not.
U.S. Pat. No. 4,370,160 to Ziemelis teaches microparticles, such as microspheres and microcapsules, comprising a solid organopolysiloxane are prepared by irradiating a dispersion of discrete entities with ultraviolet light. The discrete entities are dispersed in a UV-transparent fluid continuous phase and are sphere-like particles of a UV-curable, liquid organopolysiloxane composition containing a material to be encapsulated. The microparticles may be elastomeric or resinous and are useful as filler particles and time-release capsules. The present invention does not teach the preparation of microparticles.
U.S. Pat. No. 4,618,642 to Schoenherr, teaches an aqueous silicone elastomeric emulsion that is obtained by mixing an anionic emulsion containing dispersed particles of hydroxyl endblocked polydiorganosiloxane, dialkyltindicarboxylate, silanes of the formula RSi(OR').sub.3 where R is a monovalent hydrocarbon radical of from 1 to 4 carbon atoms inclusive and R' is a lower alkyl radical of from 1 to 4 carbon atoms inclusive or a radical of the formula --N.dbd.CR.sub.2 and inert, non-siliceous filler. Unlike the '642 patent, the present invention does not teach using silanes of the formula Rsi(OR').sub.3 in the composition.
U.S. Pat. No. 4,782,112 to Kondo et al. teaches a mixture of (A) a silicone water-based emulsion composed of water, emulsifying agent, and diorganopolysiloxane having at least 2 silicone-bonded hydroxyl groups in each molecule, (B) a silicone water-based emulsion composed of water, emulsifying agent, and organohydrogen-polysiloxane having at least 2 silicon-bonded hydrogen atoms in each molecule, and (C) a curing catalyst. It is characterized by an excellent storage stability, and by the formation on curing of a rubbery elastomeric coating film which has excellent alkali resistance, water repellency, water-repellent sealability, and durability of adhesion. The '112 patent, however, does not teach the addition of a functionalizing silane to the polysiloxane as does the present invention.
U.S. Pat. No. 4,954,565 to Liles teaches a shelf stable aqueous silicone emulsion which yields an elastomer upon removal of the water, which is produced by combining a hydroxy endblocked polydiorganosiloxane which is present as an emulsion of dispersed particles in water, a crosslinker, and a tin catalyst, the tin catalyst being in the form of a divalent tin atom combined with organic radicals. The emulsion, after crosslinking of the polydiorganosiloxane, can be reinforced with colloidal silica without affecting the shelf life of the reinforced emulsion. The '565 patent, however, differs from the present invention because the composition of the '565 patent does not include a dialkoxy functionalizing silane. Moreover, the '565 patent does not teach adding dihydrolyzable silanes to silanol functional polymers to form non-crosslinked polymers which are now functionalized.
U.S. Pat. No. 5,084,849 to Liles teaches a silicone emulsion prepared by emulsion polymerizing a hydroxyl endblocked polydiorganosiloxane oligomer with a combination of a siloxane or siloxane precursor containing unsaturated hydrocarbon groups and a functional silicone selected from the group consisting of organosilicon hydrides and mercapto alkylsilanes or siloxanes, or with an acryl or methacryl functional siloxane. In the '849 patent, however, the functional silicone is polymerized concurrently with the siloxane. In the present invention, the functional silane is grafted onto the ends of the polymer after the siloxane polymer has finished polymerizing.
U.S. Pat. No. 5,089,537 to Liles teaches a silicone emulsion prepared by emulsion polymerizing a hydroxyl endblocked polydiorganosiloxane oligomer with a combination of a siloxane or siloxane precursor containing unsaturated hydrocarbon groups and a functional silicone selected from the group consisting of organosilicon hydrides and mercaptoalkylsilanes or siloxanes, or with an acryl or methacryl functional siloxane. When the emulsion of the copolymer produced is combined with a photoinitiator, the copolymer can be crosslinked by exposure to ultraviolet radiation. When the water is removed, an elastomer results. The emulsion can be used to produce coatings and sealants. Unlike the present invention which places the functionalized silane on the ends of the polydiorganosiloxane molecule, the '537 patent teaches that the functionalized silane is emulsion polymerized with the polydiorganosiloxane.
Japanese Kokai Patent No. SHO 61[1986]-228064 teaches a composition containing organopolysiloxane, polyvinyl alcohol and/or cellulose derivatives, sensitizer, and water to obtain photocurable silicone emulsion compositions. The present invention does not contain polyvinyl alcohol and/or cellulose derivatives in the composition.